Fast deposited microcrystalline silicon solar cells

Microcrystalline silicon solar cells with AM 1.5 conversion efficiency above 5% have been deposited at deposition rates in excess of 10 /spl Aring//s. This is achieved by VHF-GD at an excitation frequency of 130 MHz. By increasing the plasma power at a dilution ratio of 7.5 % silane/(silane+hydrogen) there first appears a morphological transition from a-Si:H to /spl mu/c-Si:H and then an increase in deposition rate. Crystallographic properties and solar cell efficiencies vary thereby in a significant manner.